WSL2-Linux-Kernel/drivers/firmware
Ard Biesheuvel b0dddf6c14 efi/arm: Fix absolute relocation detection for older toolchains
When building the ARM kernel with CONFIG_EFI=y, the following build
error may occur when using a less recent version of binutils (2.23 or
older):

   STUBCPY drivers/firmware/efi/libstub/lib-sort.stub.o
 00000000 R_ARM_ABS32       sort
 00000004 R_ARM_ABS32       __ksymtab_strings
 drivers/firmware/efi/libstub/lib-sort.stub.o: absolute symbol references not allowed in the EFI stub

(and when building with debug symbols, the list above is much longer, and
contains all the internal references between the .debug sections and the
actual code)

This issue is caused by the fact that objcopy v2.23 or earlier does not
support wildcards in its -R and -j options, which means the following
line from the Makefile:

  STUBCOPY_FLAGS-y		:= -R .debug* -R *ksymtab* -R *kcrctab*

fails to take effect, leaving harmless absolute relocations in the binary
that are indistinguishable from relocations that may cause crashes at
runtime due to the fact that these relocations are resolved at link time
using the virtual address of the kernel, which is always different from
the address at which the EFI firmware loads and invokes the stub.

So, as a workaround, disable debug symbols explicitly when building the
stub for ARM, and strip the ksymtab and kcrctab symbols for the only
exported symbol we currently reuse in the stub, which is 'sort'.

Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1476805991-7160-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-19 14:49:44 +02:00
..
broadcom tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
efi efi/arm: Fix absolute relocation detection for older toolchains 2016-10-19 14:49:44 +02:00
google firmware-gsmi: Delete an unnecessary check before the function call "dma_pool_destroy" 2016-09-09 16:08:45 +01:00
meson firmware: Amlogic: Add secure monitor driver 2016-09-01 14:23:39 -07:00
Kconfig firmware: Amlogic: Add secure monitor driver 2016-09-01 14:23:39 -07:00
Makefile firmware: Amlogic: Add secure monitor driver 2016-09-01 14:23:39 -07:00
arm_scpi.c firmware: arm_scpi: add missing of_node_put after calling of_parse_phandle 2016-08-08 14:31:09 +01:00
dcdbas.c dcdbas: Make use of smp_call_on_cpu() 2016-09-05 13:52:40 +02:00
dcdbas.h
dell_rbu.c
dmi-id.c dmi-id: don't free dev structure after calling device_register 2016-09-08 10:35:50 +02:00
dmi-sysfs.c
dmi_scan.c firmware: dmi_scan: Save SMBIOS Type 9 System Slots 2016-01-15 22:08:45 +01:00
edd.c
iscsi_ibft.c ibft: Expose iBFT acpi header via sysfs 2016-05-16 11:14:29 -04:00
iscsi_ibft_find.c
memmap.c
pcdp.c
pcdp.h
psci.c drivers: firmware: psci: initialise idle states using ACPI LPI 2016-07-21 23:29:38 +02:00
qcom_scm-32.c firmware: qcom: scm: Expose PAS command 10 as reset-controller 2016-06-24 22:53:52 -05:00
qcom_scm-64.c firmware: qcom: scm: Expose PAS command 10 as reset-controller 2016-06-24 22:53:52 -05:00
qcom_scm.c firmware: qcom_scm: make it explicitly non-modular 2016-08-23 15:46:32 -05:00
qcom_scm.h firmware: qcom: scm: Expose PAS command 10 as reset-controller 2016-06-24 22:53:52 -05:00
qemu_fw_cfg.c driver core update for 4.7-rc1 2016-05-20 21:26:15 -07:00
raspberrypi.c
scpi_pm_domain.c firmware: scpi: add device power domain support using genpd 2016-06-21 10:26:51 +01:00